Lamp support arm



FIG. 1 is a side elevation view of the lamp support arm in accordance with my design, illustrating the lamp and backplate as environment for the support arm;

FIG. 2 is a top plan view of the lamp support arm in accordance with my design;

FIG. 3 is a front elevation view of the lamp support arm in accordance with my design;

FIG. 4 is a side elevation view of the lamp support arm in accordance with my design;

FIG. 5 is a rear elevation view of the lamp support arm in accordance with my design; and,

FIG. 6 is a bottom plan view of the lamp support arm in accordance with my design.

The right and left elevation views are symmetrical.

The broken line environmental showing is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for the lamp support arm, as shown and described. 